Micofabricated Cantilever-Based Scanner for forward-looking 3D Endoscopic Optical

描述（由申请人提供）：本项目旨在开发一种新型二维光学扫描仪，以实现内窥镜前视3D光学相干断层扫描。内窥镜OCT （EOCT）通过“光学活检”提供了微创诊断的潜力，该“光学活检”由各种组织的原位层析地下成像组成。基于导管的EOCT是通过放置在内窥镜内的导管输送光束来实现的。导管OCT探头已开发使用侧看几何形状，这是适合成像窄腔血管。前视探头对胃、结肠、膀胱等大型或中空器官粘膜的成像能力将大大增强，但由于导管尺寸的限制，实施起来较为复杂。实现前瞻性EOCT的方法已有报道，由于在小导管直径（2.9 mm）内插入二维光学扫描仪的困难，通常提供一维扫描。给定导管集成的二维光学扫描仪，参考光束位于内窥镜外，通过纵向尺寸扫描可以获得高分辨率的三维EOCT成像。这种成像方法将允许准确的非侵入性诊断癌症和其他病变，这些病变渗透到上皮或近亚上皮层的深度有限。

DESCRIPTION (provided by applicant): This project aims at the development of a novel two-dimensional optical scanner to enable endoscopic forward-looking 3D Optical Coherence Tomography. Endoscopic OCT (EOCT) provides the potential for minimally invasive diagnostics by "optical biopsy" consisting of tomographic sub-surface imaging in situ in a variety of tissues. Catheter-based EOCT is performed by delivering the light beam through a catheter placed inside an endoscope. Catheter OCT probes have been developed using a side-looking geometry, which is appropriate for imaging narrow-lumen vessels. A forward-looking probe would greatly enhance the ability of imaging mucosa of large or hollow organs such as stomach, colon, and bladder, but the implementation is complicated by the catheter size constraints. Approaches to achieve forwardlooking EOCT have been reported and typically offer uni-dimensional scanning due to the difficulty of inserting a two-dimensional optical scanner within the small catheter diameter (2.9 mm). Given a catheter-integrated, two-dimensional optical scanner, high resolution 3D EOCT imaging can be obtained using longitudinal dimension scanning with the reference beam located outside the endoscope. This imaging approach will allow accurate non-invasive diagnoses of cancers and other pathologies limited in depth of penetration to epithelial or near sub-epithelial layers. The novel design for the two-dimensional optical scanner proposed here is based on microfabricated cantilevers. Static deflection and resonance frequency calculations indicate that, for a reasonable set of parameters, the proposed scheme provides a size and power consumption advantage over the competing approaches and excellent scanning range and speed performance. This project is focused on the microfabrication and characterization of a two-dimensional scanner optimized for catheter OCT imaging. The microfabrication processing steps will be designed to include a range of parameters selected based on the calculated effects of actuator geometry and film thicknesses on scanning performance. The mechanical and optical properties of the devices will be characterized with a suite of available measurement tools. A detailed optical simulation of the EOCT system will be performed based on actual performance of the optical scanner. Optimized devices will be integrated with suitable optical components and incorporated into a high-speed Fourier-Domain OCT scanner to assess image quality.